Semiconductor processing and packaging techniques are continually evolving to meet industry demands for devices with improved performance and reduced size and cost. Electronic products require packaged semiconductor assemblies with a high density of devices in a relatively small space. For example, the space available for memory devices, processors, displays and other semiconductor devices is continually decreasing in cell phones, personal digital assistants, laptop computers and many other products. Accordingly, a need exists to increase the density of semiconductor devices and components within the confined footprint of a semiconductor assembly. One technique for increasing the density of semiconductor devices within a given footprint is to stack semiconductor dies. A challenge with this technique, however, is providing adequate electrical interconnects within and between the stacked dies.
One approach to addressing the challenges associated with stacked semiconductor dies is to use a leadframe having a support paddle that supports the lowest die, and leadfingers that provide electrical connections between the stack of dies and devices external to the finished package. While this arrangement has proven to be suitable for many purposes, the continual pressure to reduce not only the footprint of the package but also the overall volume of the package has created the need for still smaller and more efficiently packaged dies.